The Gaslight series has become immensely addictive.
Having said that, Murder on Washington Square sees a significant development in the socially unacceptable friendship between the Knickerbocker-turned-midwife and the Irish police captain. And Murder on Mulberry Bend has a significant development in the mystery around Sarah's husband's murder years before.
The other aspect of the series that recently dawned on me is that Thompson always takes some . The climactic scenes where the murderers are revealed tend to be dramatic, over-the-top, socially shocking scenarios (everything from an incestuous couple running out to the rooftops in a thunderstorm, to a cross-dressing actor pulling a Norman Bates). In a way, the underlying sensationalism complements the prim and proper veneer of 19th century society rules.
Bizarre and lurid as the endings can get, however, I was a little disappointed that I picked up on the clues and guessed the identity and motives for the culprits in Books 4 and 5 long before the middle of the story. Murder on Marble Row, however, had an unexpected conclusion. So I can rest easy that I won't get bored with the rest of the series!